Heater for gaseous mediums having helically wound pipe coils



April 12, 1966 w. GoLlBRzucl-l HEATER FOR GASEOUS MEDIUMS HAVING HELICALLY WOUND PIPE COI med Feb. 2s, 4

INVENTOR. WERNER GOLI BRZ UCH ATT ORN EYS ldirection of the recuperator.

United States 'Patent O This invention relates to a heater for gaseous mediums, wherein the heater has a cylinder or body in which are disposed helically wound pipe coils forming a radiation portion and a convection portion of the heater. The medium to be heated ilows through the pipe coils of the 'convection portion countercurrent to the heating gases which travel longitudinally through the heater, and flows through the pipe coils of the radiation portion in the same direction as that of the heating gases.

In a known version of this type of heater intended pri- -marily for heating gaseous mediums which contain hydrocarbons, both the convection .portion and the radiation portion have a single helically wound conduit whose diameter is adapted to a desired output. Thus, the medium to be heated flows through a single conduit, first through the helical coil of the convection portion in countercurrent to the heating gases, and then through the helical coil of the radiation portion in the same direction as the heating gases (German P-atent 1,063,618).

Furthermore, there is a known radiation recuperator (German IPatent 1,040,733) in which the inlet for the medium to be heated is connected to a distributor manifold `disposed longitudinally within the recuperator. Tubes extend from the distributor manifold and discharge into a collecting manifold which runs parallel to the distributor manifold and is connected to an outlet. Here a number of single conduits, each of which encompasses one screw-turn, is arranged in parallel and is spaced at a substantial distance from one another in the longitudinal -If the coil turns of the individual conduits arranged in parallel to one another are to be placed as closely together as possible in order to obtain a large output volume, and also at the same time achieve favorable conditions of -heat transmission, then there must be a plurality of distributor and collecting manifolds. Alternatively, the points of connection between -the individual helical conduits and the distributor tube or collecting manifold running longitudinally within the recuperator must be placed so close to one another that both manufacture and operation of such recuperators become quite costly and in part difcult. In this regard, it must be lkept in mind that the medium to be heated must traverse flow paths which are as identical as possible, and must encounter identical pressure conditions along the ilow paths so that there is uniform distribution of the medium to be :heated and no variation in the transmission of heat. However, the greater the number of tubes through which the medium to be heated must llow, the more difficult it is to achieve uniform distribution in the individual conduits of the medium to be heated.

Moreover, in heaters having pipe coils which form the radiation port-ion and the convection por-tion thereof, suspension or securing of the pipe coils frequently presents a problem, the solution of which involves considerable expense. It is known to brace the -spiral coils of the pipes against one another by crosspieces, and to mount the lower spiral coils on a support bracket.

My invention resides in a heater having helically wound pipe coils which form a convection portion and a radiation portion, wherein the medium to be heated travels through the convection portion countercurrent to the heating gases ilowiug lengthwise through the heater, and wherein the medium to be heated travels through the radiation portion concurrent with the flow of the heating gases. I use a large number of juxta-positioned pipe coils to achieve a high output, and obtain a substantially uniform distribution of the Imedium to be heated under uniform pressure conditions during flow of the medium through the heater. Additionally, difficulties either in manufacturing or in operation at the points of connection between the distributor and/or.collecting manifolds and the pipe coils of the heater are not encountered.

Furthermore, my -invention secures or suspends the pipe coils so that previously-used crosspieces, support brackets and the like are eliminated to a large extent.

To achieve the foregoing in a heater of the identified type, the spiral tubes of the radiation portion and the convection portion comprise a number of individual helical conduits or pipes disposed in a flow parallel arrangement wherein the pipes of the convection portion extend parallel to one another and the .pipes of the radiation portion do likewise. Preferably, each of the pipes of the convection portion and of the radiation portion forms a passageway lengthwise and cross-sectionwise for flow of the medium to be heated there-through, which is substantially the same as the passageway formed by each of the other pipes of the convection portion and of the radiation portion, respectively. Such length and cross-section features in each of the convection pipes and in each of the radiation pipes effects the uniform distribution of the medium under uniform pressure conditions.

The individual conduits of the convection portion open into an annular manifold disposed at right angles to the length of the heater. Preferably, these individual helical conduits of the convection portion connect into short vertical or almost vertical pieces of pipe attached to the annular manifold, which pieces of pipe lead into the individual helical conduits.

In recuperators equipped Iwith straight exchanger tubes, it is known to provide an upper and a lower distributor manifold or collector manifold between which are disposed the straight tubes, and through which the medium which is to be hea-ted ows.

The ends of the individual helical conduits of the convection portion are connected to the conduits of or to a water drainage manifold of the radiation portion by transmission pipes distributed uniformly along the inner wall of the heater. Thus, in addition to achieving a uniform path of iiow for the medium to be heated in all of the individual conduits, my invention presents an opportunity for suspending the coils of the radiation portion whereby a uniform distribution of the transfer pipes on a circular plane prevents tipping over of the pipe coil package or the pipe coil group of the radiation portion, and without use of a support bracket. If desired, crosspieces may be used between the individual spirals.

It is particularly advantageous that the manifold of the convection portion comprise two annular tubes disposed concentrically with one tube within the other. Likewise, the helically wound individual pipes of the convection portion preferably are arranged in two groups positioned concen-trically with one group within the other. Then, one portion of the transmission pipes between the convection portion and the radiation portion runs along that side Iof the individual conduits of the radiation portion which is adjacent the central axis of the heater, while the other portion of the transfer pipes -is disposed on that side of the individual conduits of the radiation portion which is adjacent the inner wall of the heater. -In other words, the transmission pipes are divided in half, whereby one half faces the central axis of the heater and is uniformly spaced apart on a smaller circle, and the other half likewise is uniformly spaced apart along a larger circle between the coils of the individual helical conduits of the radiation portion and the inner Wall of the heater.

Preferably, the diameter of the winding of the individual helical conduits of the radiation portion is between that of the smallest and that of the largest diameter of the windings of the two concentrically disposed groups of conduits of the convection portion.

When the medium which is to be heated has been heated, it leaves the radiation portion and enters a collecting manifold located on the longitudinal axis of the heater. The individual conduits of the radiation portion lead radially into this collecting manifold and the radially disposed pipe sections used for this purpose are located in the direction of ow of the heating gases in front of a Well-known partition member which directs the hot gases from the radiation portion into the convection portion and cooperates to define the convection portion. The

outlet pipe for the heated medium extends into connection with the collecting manifold.

In the accompanying drawings, I have shown a preferred embodiment of my invention, in which:

FIGURE 1 is a longitudinal section; and

FIGURE 2 is a section view along the line II-II of FIGURE 1.

Referring to FIGURES 1 and 2, a cylindrical heater -body 1, supported on feet 2 and comprising wall portions 3 and 4, forms an inner chamber 5 which is closed at its upper end by a hood 6 from which a heating gas outlet 7 projects. The heater body 1 includes a convection portion A and a radiation portion B and heating gases which iiow through the inner chamber in the direction of arrows P and P are either produced by a burner 8 or are delivered by a conduit (not shown) located in the floor of the heater. A delivery pipe 10 for the medium to be heated passes through hood 6 or through an annular inltermediate portion 9 between the hood and wall portions 3 and 4. This delivery pipe 10 opens yinto two concentric annular rings 1'1 and 12 located in the same horizontal pl-ane of the heater. The rings 11 and 12 together form an annular distributor manifold of the convection portion A. Equally spaced along the periphery of these two annular rings 11 and 12 are branch pipes 13, which are at right angles to or approximately at right angles to the rings 1-1 and 12, and form an entry part of the coiled Y individual conduits 14. Conduits 14 are adjacent a partition member '15 and are concentric with individual conduits 14", the latter, however, being disposed on a larger circle and adjacent to the inner side of wall portion 3. The end of each helically wound individual conduit 14 and 14l of the convection portion opens into vertical transfer or transmission pipes 16 and 16, respectively. As shown, the transfer pipes are disposed in circles corresponding to those of the helical individual conduits 14 and d4", respectively, and FIGURE 2 shows the transfer pipes 16' and 16 evenly distributed on two respective circles and extending into a water drainage manifold 117. Conventional outlet pipe 18 projects from the manifold '17.

Vertical branch pipes 19 for individual helical conduits 20 are disposed at equal intervals about the circumference of the drainage manifold 17. The distance between these branch pipes 19 is such that the connecting points of the branch pipes present no difficulties for the manifold 17, either when being assembled or during operation, even though the pipe coils 20 are close to one another in the longitudinal direction of the heater. The same situation exists regarding the annular rings 11 and 12 and branch pipes 13 of conduits 14.

The drainage manifold 17 may be dispensed rwith, if desired, and in that case, conduits 16' and i16" connect directly into conduits 20 at the elevation of manifold 17.

The diameter of the windings of individual conduits 20 is such -that 4these conduits are located in the intermediate space between vertical transfer pipes 16 and 16". Due

to the equal distribution of pipes 16' and 16 in a circular pattern, and due to the arrangement of the individual conduits 20 in pipe groups of radiation portion B, I suspend the conduits 20 of the radiation portion by using transfer pipes 16 and 16 as their supporting means. Furthermore, the goal of maintaining an even flow path for the medium to be heated, in view of the large volume of output, is achieved by the upper ends of the individual conduits 20 leading radially inwardly into conduit portions 21 which, in turn, open into a collector Imanifold 22 connected to an outlet or delivery pipe 24 by a vconduit 23 which passes through the partition member 15.

While I have shown and described a preferred embodiment of my invention, it may be otherwise embodied or practiced within the scope of the following claims.

I claim:

1. In a heater for a gaseous medium, said heater having a shell through at least a portion of which travel hot gases for heating said gaseous medium, the invention comprising a radiation portion and a convection portion in said shell, said two portions being in hot gas ow communication for travel of said hot gases from said radiation portion into said convection portion, a rst manifold adapted to be connected to a source of said gaseous medium, a plurality of individual helically wound pipe coils disposed substantially in said convection portion, each connected into said first manifold and formin-g convection coils, a plurality of individual helically wound pipe coils disposed substantially in said radiation portion, being adapted to be connected to an outlet for said gaseous medium and forming radiation coils, a second manifold, conduit means connecting said convection coils and said second manifold for ilow of said gaseous medium from said convection coils into said second manifold, each of said radiation coils having an opening into said second manifold, said convection coils being arranged substantially parallel to one another and said radiation coils being arranged substantially parallel to one another, each of said convection coils and each of said radiation coils forming a passageway lengthwise and cross-sectionwise for ow of said gaseous medium therethrough which is substantially the same as the passageway formed by each of the other convection coils and the other radiation coils respectively, said convection coils having a position in said shell such that said gaseous medium flows therethrough countercurrent to travel of said hot -gases and said radiation coils having a position in said shell such that said gaseous medium iiows therethrough concurrent with said hot gases.

2. In a heater for a gaseous medium, said heater having a shell through at least a portion of which travel hot gases for heating said gaseous medium, the invention comprising a radiation portion and a convection portion in said shell, said two portions being in hot gas flow cornmunication for travel of said hot gases from said radiation portion into said convection portion, a manifold adapted to be connected to a source of said gaseous medium and comprising at least two tubes spaced apar-t and disposed substantially concentrically with one tube within 4the other, a plurality of individual helically wound pipe coils disposed substantially in said convection portion and forming convection coils, said convection coils comprising at least two groups one of whose individual coils are lconnected into one of said two tubes and the other of whose individual coils yare connected into the other of said two tubes, said convection coils being arranged such that said two groups lie concentrically with one group within the other and such that the convection coils in each group are substantially parallel to one another, a plurality of individual helically wound pipe coils disposed substantially in said radiation portion and forming radiation coils, a plurality of transmission conduits connecting `said convection coils and said radiation coils for flow of said gaseous medium from said convection coils into said radiation coils, said transmission conduits extending substantially longitudinally of said heater and comprising at least two groups spaced apart from and substantially parallel to one another, one of said two groups of transmission conduits joining the convection coils of said inner group to said radiation coils and the other group of said transmission conduits joining the convection coils of said outer group to said radiation coils, said convection coils having a position in said shell such that said gaseous medium ows therethrough countercurrent to travel of said hot gases and said radiation coils having a position in `said shell such that said gaseous medium iows therethrough concurrent with said hot gases.

3. The invention of claim 2 characterized by said radiation coils being positioned between said two groups of said transmission conduits.

4. The invention of claim 2 characterized by a second manifold interposed between said transmission conduits and said radiation coils and having said transmission conduits and said radiation coils connected thereinto.

5. The invention of claim 2 characterized by said radiation coils being positioned between said two groups of said ltransmission conduits and by a second manifold interposed between said transmission conduits and said radiation coils yand having said transmission conduits and said radiation coils connected thereinto.

6. The invention of claim 2 characterized by the transmission conduits of each of said two groups being substantially equally spaced apart from one another.

7. The invention of claim 2 characterized by each of said convection coils and each of said radiation coils forming a lpassageway lengthwise and cross-sectionwise for flow of said gaseous medium therethrough which is substantially the same as the passageway formed by each of the other convection coils and radiation coils, respectively.

8. The invention of claim 3 characterized by each of said convection coils land each of said radiation coils forming a passageway lengthwise and cross-sectionwise for ow of Vsaid gaseous medium therethrough which is substantially the same as the passageway formed by each of the other convection coils and radiation coils, respectively.

9. The invention of claim 3 characterized by the transmission conduits of each of said two groups being substntially equally spaced apart from one another.

10. The invention of claim 9 characterized by each of said convection coils and each of said radiation coils forming a passageway lengthwise and cross-sectionwise for flow of said gaseous medium therethrough which is substantially the same as the passageway formed by each of the other convection -coils and radiation coils, respectively.

11. The invention of claim 2 characterized by said radiation coils being connected to a collector manifold located substantially on the longitudinal axis of said heater for discharge of said gaseous medium from said radiation coils thereinto, said collector manifold being adapted to be joined to said outlet.

References Cited by the Examiner UNITED STATES PATENTS 2,374,882 5/ 1945 Nagel 122-250 2,902,981 9/ 1959 Throckmorton et al. 122-356 FOREIGN PATENTS 1,256,104 2/1961 France.

604,373 2/ 1948 Great Britain.

OTHER REFERENCES Kuhne, 1,063,618, German printed application.

FREDERICK L. MATTESON, IR., Primary Examiner.

CHARLES I. MYHRE, Examiner. 

1. IN A HEATER FOR A GASEOUS MEDIUM, SAID HEATER HAVING A SHELL THROUGH AT LEAST A PORTION OF WHICH TRAVEL HOT GASES FOR HEATING SAID GASEOUS MEDIUM, THE INVENTION COMPRISING A RADIATION PORTION AND A CONVECTION PORTION IN SAID SHELL, SAID TWO PORTIONS BEING IN HOT GAS FLOW COMMUNICATION FOR TRAVEL OF SAID HOT GASES FROM SAID RADIATION PORTION INTO SAID CONVECTION PORTION, A FIRST MANIFOLD ADAPTED TO BE CONNECTED TO A SOURCE OF SAID GASEOUS MEDIUM, A PLURALITY OF INDIVIDUAL HELICALLY WOUND PIPE COILS DISPOSED SUBSTANTIALLY IN SAID CONVECTION PORTION,, EACH CONNECTED INTO SAID FIRST MANIFOLD AND FORMING CONVECTION COILS, A PLURALITY OF INDIVIDUAL HELICALLY WOUND PIPE COILS DISPOSED SUBSTANTIALLY IN SAID RADIATION PORTION, BEING ADAPTED TO BE CONNECTED TO AN OUTLET FOR SAID GASEOUS MEDIUM AND FORMING RADIATION COILS, A SECOND MANIFOLD, CONDUIT MEANS CONNECTING SAID CONVECTION COILS AND SAID SECOND MANIFOLD FOR FLOW OF SAID GASEOUS MEDIUM FROM SAID CONVECTION COILS INTO AID SECOND MANIFOLD, EACH OF SAID RADIATION COILS HAVING AN OPENING INTO SAID SECOND MANIFOLD, SAID CONVECTION COILS BEING ARRANGED SUBSTANTIALLY PARALLEL TO ONE ANOTHER AND SAID RADIATION COILS BEING ARRANGED SUBSTANTIALLY PARALLEL TO ONE ANOTHER, EACH OF SAID CONVECTION COILS AND EACH OF SAID RADIATION COILS FORMING A PASSAGEWAY LENGTHWISE AND CROSS-SECTIONWISE FOR FLOW OF SAID GASEOUS MEDIUM THERETHROUGH WHICH IS SUBSTANTIALLY THE SAME AS THE PASSAGEWAY FORMED BY EACH OF THE OTHER CONVECTION COILS HAVING A POSITION IN RESPECTIVELY, SAID CONVECTION COILS HAVING A POSITION IN SAID SHELL SUCH THAT SAID GASEOUS MEDIUM FLOWS THERETHROUHG COUNTERCURRENT TO TRAVEL OF SAID HOT GASES AND SAID RADIATION COILS HAVING A POSITION IN SAID SHELL SUCH THAT SAID GASEOUS MEDIUM FLOWS THERETHROUGH CONCURRENT WITH SAID HOT GASES. 